Turing's Last Programs

By Jack Copeland

During the final years of his life Turing was working on what would now be called Artificial Life or A-Life. He used the Ferranti Mark I computer belonging to the Manchester University Computing Machine Laboratory to simulate a chemical mechanism by which the genes of a zygote may determine the anatomical structure of the resulting animal or plant. He described these studies as 'not altogether unconnected' to his work on neural networks, as 'brain structure has to be ... achieved by the genetical embryological mechanism, and this theory that I am now working on may make clearer what restrictions this really implies'. During this period Turing achieved the distinction of being the first to engage in the computer-assisted exploration of non-linear dynamical systems (his theory used non-linear differential equations to express the chemistry of growth). He died while in the middle of this groundbreaking work, leaving a large pile of handwritten notes and some programs. This material is still not fully understood.

The program below, which is in Turing's own hand, formed part of his study of the development of the fir cone.